Transdermal dispensing apparatus and methods

ABSTRACT

An applicator for dispensing a therapeutic agent to an animal comprising a housing including first and second sections coupled together, the first and second sections defining a channel therebetween that includes at least one outlet; a hub integral with the first section and extending therefrom, the hub defining a conduit; and a bent path connecting the conduit to the channel. In accordance with this embodiment, the conduit, the bent path and the channel are fluidly connected.

FIELD OF THE INVENTION

The present invention relates generally to apparatuses and methods fordispensing therapeutic agents to animals, and particularly applicatorsand methods for transdermally administering therapeutic agents todomestic animals.

BACKGROUND

Drug delivery devices and applicators for dispensing known quantities oftherapeutic agents to animals are well known in the art. While there arenumerous ways to deliver these therapeutic agents to the coats and skinsof the animals, many of these methods are either ineffective and/orpresent safety risks to the animal or user during or after thedispensing activity. More particularly, because a physical connectionmust be achieved between the applicator tip and the drug delivery deviceduring the dispensing activity, there is inherently a risk that theconnection will be inadequate, thereby permitting some of thetherapeutic agent to leak out of the device and into physical contactwith the user. Not only is this leakage wasteful and messy, it alsoplaces the user at a heightened risk of suffering from a skin irritationor other such health concern, particularly if the user comes into directcontact with the agent. These health and safety risks can be ofparticular concern when a controlled substance is used as the dispensingagent.

In addition to leakage concerns, many conventional drug delivery devicesalso have a tendency to leave some residual therapeutic agent inside thebody of the device after dispensing is completed. This is not onlywasteful both in terms of product and cost, but also presents anincreased safety risk to any individual who may contact the device afterit has been used. More particularly, if the device still contains apoisonous or skin irritating ingredient, a person may suffer a serioushealth risk (or even death) if they handle the component after it hasbeen discarded. Further, a residual amount of a controlled substanceremaining in the dispenser after dispensing may create an issue ofunauthorized use of a controlled substance.

SUMMARY OF THE INVENTION

The present invention overcomes or ameliorates at least one of the priorart disadvantages or provides a useful alternative thereto by providingan apparatus and associated methods for dispensing therapeutic agents,and particularly applicators and methods for transdermally administeringtherapeutic agents to domestic animals.

In accordance with one aspect of the present invention, an applicatorfor dispensing a therapeutic agent to an animal is provided. Theapplicator comprises a housing including first and second sectionscoupled together, the first and second sections defining a channeltherebetween that includes at least one outlet; a hub integral with thefirst section and extending therefrom, the hub defining a conduit; and abent path connecting the conduit to the channel. In accordance with thisembodiment, the conduit, the bent path and the channel are fluidlyconnected.

In accordance with yet another aspect of the present invention, a methodof manufacturing an applicator for transdermally dispensing atherapeutic agent to an animal is provided. The method comprisesproviding a first housing section including a hub portion attachable toa syringe and a pair of spaced ribs with a groove formed therebetween,the hub portion further defining a conduit; providing a second housingsection including a ledge, the ledge being formed by a pair of spacedgrooves; mating the pair of spaced ribs with the pair of spaced groovesto form a channel for dispensing the therapeutic agent, the channelbeing fluidly connected to the conduit by way of a bent path; andcoupling the first housing section to the second housing section to forman applicator body, the applicator body defining at least one outlet fordispensing the therapeutic agent.

In accordance with still another aspect of the present invention, amethod is provided for dispensing a therapeutic agent from an applicatorof the type having a housing including first and second sections coupledtogether to form a channel and a hub extending from the housing, the hubbeing attachable to a syringe. The method comprises attaching the hub toa syringe containing a therapeutic agent; placing an outlet of theapplicator on or near the animal; causing the therapeutic agent to bereleased from the syringe into the applicator; passing the therapeuticagent through the hub, through a bent path and then into the channel;and dispensing the therapeutic agent from the applicator through theoutlet.

BRIEF DESCRIPTION OF DRAWINGS

The above-mentioned aspects of the present teachings and the manner ofobtaining them will become more apparent and the teachings will bebetter understood by reference to the following description of theembodiments taken in conjunction with the accompanying drawings,wherein:

FIG. 1 is a perspective view of an assembled applicator connected to afluid delivery device and positioned on an animal for dispensing atherapeutic agent onto the animal in accordance with the teachings ofthe present invention;

FIG. 2 is a perspective view an assembled applicator in accordance withthe present invention;

FIG. 2A is an end view of an outlet from the assembled applicator ofFIG. 2 taken along line 2A;

FIG. 3 is a perspective view of the bottom section of an applicator inaccordance with the present invention;

FIG. 4 is another perspective view of the bottom section of anapplicator in accordance with the present invention;

FIG. 4A is a cross-sectional view of the top section of an applicator ofFIG. 5 taken along line 5A;

FIG. 4B is a cross-sectional view of the bottom section of an applicatorof FIG. 4 taken along line 4B;

FIG. 4C is a cross-sectional view of the assembled applicator of FIG. 2taken along line 4C;

FIG. 5 is a perspective view of the top section of an applicator inaccordance with the present invention;

FIG. 5A is a cross-sectional view of a different embodiment of a topsection of an applicator;

FIG. 5B is a cross-sectional view of a different embodiment of a bottomsection of an applicator;

FIG. 5C is a cross-sectional view of the assembled applicator after thetop section of FIG. 5A is ultrasonically welded with the bottom sectionof FIG. 5B;

FIG. 6 is a cross-sectional side view of an assembled applicator of FIG.2 taken along line 6;

FIG. 7A is a cross-sectional view of another embodiment of a top sectionof an applicator;

FIG. 7B is a cross-sectional view of another embodiment of a bottomsection of an applicator;

FIG. 7C is a cross-sectional view of the assembled applicator after thetop section of FIG. 7A is ultrasonically welded with the bottom sectionof FIG. 7B;

FIG. 8 is a cross-sectional view of an assembled applicator inaccordance with the present invention;

FIG. 8A is a magnified cross-sectional view of a portion of theassembled applicator of FIG. 8 and indicated by circle 8A; and

FIG. 8B is a cross-sectional view of the assembled applicator of FIG. 8showing a plane passing through the joint.

DETAILED DESCRIPTION

The embodiments of the present teachings described below are notintended to be exhaustive or to limit the teachings to the precise formsdisclosed in the following detailed description. Rather, the embodimentsare chosen and described so that others skilled in the art mayappreciate and understand the principles and practices of the presentteachings.

The present invention is generally directed to drug delivery devices fordispensing liquid based formulations to animals, particularlydomesticated or companion animals such as, but not limited to, dogs,cats, horses and the like. While certainly not intended to be requiredherein, the present invention is particularly useful for transdeimallydelivering doses of controlled veterinary substances (e.g., Fentanyl) tothe coat and skin of an animal, which may include a human. As such, itshould be understood and appreciated herein that the drug deliverydevices, systems and methods of the present invention can also be usedwith other types of fluids, liquids or gels without straying from theteachings of the present invention. Some non-limiting examples of othersuch substances envisioned to be useful in accordance with the presentteachings include, but are not limited to, therapeutic agents,pesticides, parasiticides, glues, solvents, lubricants, medicaments andthe like. For simplicity purposes, the present disclosure will primarilyfocus on therapeutic agents as the illustrative and non-limitingdispensing substance; however, as is clearly explained above, theteachings of the present invention are not intended to be limited tothese therapeutic applications alone.

In certain exemplary embodiments of the present invention, the drugdelivery device includes an applicator device or tip that is compatiblewith a standard luer lock syringe and consists of a housing that allowsthe formulation to be spread over a large surface area of the animal'sskin or coat. To accomplish this, the applicator body includes one ormore outlets that are in the form of legs or tines configured topenetrate the fur of the animal and thereby deliver the drug directly tothe animal's skin or coat. In certain aspects of the present invention,the outlet(s) further includes a pair of spaced prongs or feet thatextend from its distal end, thereby allowing the therapeutic agent to befreely dispensed onto the surface of the animal. More particularly,because the spaced feet extend outwardly from the distal end ofapplicator, they are the only structural portion of the assembledapplicator that directly contact and seal against the surface of theanimal. Moreover, since the outlet opening is positioned between thespaced apart prongs and in such a manner that it does not directlycontact or seal against the surface of the animal during a dispensingoperation, the therapeutic agent is able to be freely dispensed andspread onto the animal without being physically impeded or interrupted.

A non-limiting illustration of an assembled applicator coupled to afluid delivery device in accordance with the present teachings is shownin FIG. 1. More specifically, FIG. 1 depicts a perspective view of auser 100 dispensing a therapeutic agent onto an animal 102. Inaccordance with this exemplary and non-limiting illustration, a fluiddelivery device 104 containing therapeutic agent is releasably attachedto an applicator device 106 and then placed on or near the surface ofthe animal 102. While this illustrative embodiment shows the fluiddelivery device 104 as a standard syringe, it should be understood andappreciated herein that delivery of the therapeutic agent may beaccomplished by any known fluid delivery device or connector that isreleasably attachable to the applicator device 106 and having areservoir for holding and/or storing the therapeutic agent to be dosedor dispensed. Other such non-limiting and illustrative fluid deliverydevices that may also be used in accordance with the present inventioninclude, but are not limited to, syringes, catheters, hubbed needles, IVtubes and cylinder fluid delivery devices.

As will be explained in detail below, the applicator devices 106 of thepresent invention generally consist of at least two parts or halves(i.e., sections 114 and 214) that are coupled or assembled together toform the applicator structure. Unlike many other traditional applicatordevices that consist of either one applicator part or two structurallycomplementary parts, the devices of the present invention include twosections 114, 214 that are somewhat complementary in terms of structure,yet specifically shaped in such a manner that once assembled, thetherapeutic agent can be dispensed therefrom without experiencing muchassociated leakage or residual buildup. More particularly, the sections114, 214 are structurally shaped such that when they are coupledtogether, the therapeutic agent is discouraged from leaking out of theapplicator body. In addition, the structural orientation of thedispensing passageway that is created between the first and secondsections is shaped in such a manner that substantially all of thetherapeutic agent is encouraged from being dispensed from the applicatordevice during a dispensing operation. As such, it should be understoodand appreciated herein that at least some of the unexpected advantagesof the present invention are influenced by the resultant shape andconfiguration of the dispensing passageway that is formed by theassembled applicator sections. Additional details of these advantageouscharacteristics of the present invention are discussed below.

Moving now to FIG. 2 a perspective view of a fully assembled applicator106 in accordance with the present invention is shown. The applicator106 includes a housing or body 108 defining an inlet hub 110 and anoutlet 112. As will be explained in more detail below, the inlet hub 110is attachable to the drug delivery device 104 during a dispensingoperation, whereas the outlet portion 112 is capable of penetrating thefur of an animal so that the therapeutic agent can be appropriatelydispensed therefrom and onto the surface of the animal. The applicator106 can be made from polyethylene, polypropylene, polyvinyl acetate,polystyrene, polyethylene terephthalate, polybutylene terephthalate, andpolytetrafluoroethylene, and the like.

In terms of assembly, the applicator 106 comprises first and secondsections or faces (114, 214) that are coupled or assembled together toform the housing 108. As shown in FIGS. 3 and 4, the first section 114includes a top surface 117, a bottom surface 118, a back edge 119integral with the inlet hub 110 and first and second sides 120, 122, thefirst and second sides being defined by a pair of substantially paralleloutlet ends or legs 123, 125 that extend from and partially surround asubstantially flat middle section 121 that is disposed between the firstand second sides 120, 122. Extending upwardly from the top surface 117of the first preassembled section 114 and positioned substantially alongits outer periphery are a pair of ribs 124, 126 that are spaced fromeach other in a parallel fashion. In certain exemplary embodiments, theribs 124, 126 are trapezoidal shaped and have four sides with the topand bottom sides being parallel to one another. In accordance with thisexemplary embodiment, the spaced ribs 124, 126 have a groove or channel127 that is formed therebetween.

In certain aspects of the present invention, the groove 127 is sunken ordepressed below the top surface 117 of the first section, therebycreating a channel for delivering the therapeutic agent to the outletends 123, 125 and ultimately onto the animal. To achieve the sunkenchannel formation, the groove 127 is provided as a depression below thesurface 117 and has a substantially semi-circular shape. A more detailedand non-limiting exemplary illustration of this semi-circular geometrycan be seen with reference to FIG. 4B, which illustrates across-sectional view of the first section 114 taken along line 4B ofFIG. 4. While this exemplary illustration shows the groove or channel127 being semi-circular in shape, it should be understood andappreciated herein that any known geometric shape useful forestablishing a channel that permits a fluid or other such liquid agentto travel therethrough is envisioned and can be used in accordance withthe teachings of the present invention. As such, the teachings of thepresent invention are not intended to be limited herein.

As explained above, it should be understood and appreciated herein thatthe first preassembled section 114 is configured to be coupled to andmolded with the second preassembled section 214 to form a fullyassembled applicator device 106. In addition, the channel or groove 127that is formed between the ribs 124 and 126 is positioned and shaped insuch a manner that a fluid passageway or conduit for dispensing thetherapeutic agent is formed between the fluid delivery device 104 andthe dispensing end of the outlet 112 once section 114 is coupled to andmolded with section 214.

Moving now to FIG. 5, the second preassembled section 214 has a shapethat is substantially similar to and which complements the firstpreassembled section 114; however, it does not have a correspondinginlet hub portion or a rib and groove arrangement like that of the firstsection 114. Instead, the second section 214 includes a top surface 217,a bottom surface 218, and a back edge 219 having a rounded portion 221that is substantially centrally located along the back edge 219 and isconfigured to substantially align with the inlet hub 110 portion of thefirst section during assembly. To achieve this alignment, the inlet hub110 has a flat end portion 110a that is complementarily shaped to andconfigured to seamlessly mate with a flat end portion 214a of the secondsection 214. The second preassembled section 214 also includes first andsecond sides 220, 222 that are defined by a pair of substantiallyparallel outlet ends or legs 223, 225 that extend from and partiallysurround a substantially flat middle section 227 that is disposedbetween the first and second sides 220, 222. Extending outwardly fromthe bottom surface 218 of the second section and positionedsubstantially along its outer periphery is a ledge or energy director224 that is formed by a pair of spaced grooves 226, 228. A more detailedand non-limiting exemplary illustration of this geometric configurationcan be seen with reference to FIG. 4A, which illustrates across-sectional view of the second section 214 taken along line 4A ofFIG. 5.

During assembly of the applicator 106, the pair of spaced ribs 124, 126of the first preassembled section 114 are configured to substantiallyalign with (and mate) the spaced grooves 226, 228 of the second section214, thereby forming the passageway or channel 127 for dispensing thetherapeutic agent. In accordance with certain exemplary embodiments ofthe present invention, the passageway 127 is asymmetric relative to aseamless joint 113 that attaches the first and second sections 114, 214together. A fully assembled view of the first and second sections 114,214 aligned and mated together can be seen in FIGS. 4C and 6, whichrespectively depict a cross-sectional view of the assembled applicator106 from FIG. 2 taken along line 4C and a cross-sectional side view ofthe assembled applicator 106 from FIG. 2 taken along line 6.

As can be seen particularly in FIG. 4C, after the first and secondsections are welded together, the spaced ribs 124, 126 meld into grooves226, 228 so that a seamless joint 113 is formed between the two faces114, 214, and the channel 127 is formed therebetween. In particular, asubstantially flat portion of the channel 127 is defined by the seamlessjoint 113. Once fully assembled, the channel 127 creates a fluidpassageway between the inlet hub 110 and the one or more outlets 112. Asshown in FIG. 2A, the distal end 112a of the applicator's outlet is open(see reference numeral 127a) so the therapeutic agent can be emptiedfrom channel 127 during a dispensing application.

In accordance with the teachings of the present invention, the first andsecond preassembled sections 114, 214 can be coupled together to form anassembled applicator 106 by various known plastic molding andmanufacturing methods. However, in certain aspects of the presentinvention, the applicator 106 is formed by ultrasonically welding thefirst and second preassembled sections 114, 214 together. In accordancewith this exemplary and non-limiting embodiment, the first and secondpreassembled sections 114, 214 are mated and aligned together asexplained above, and an ultrasonic weld, for instance along the ledge224, is initiated to thereby cause the sections to seamlessly meld orjoin together. As is readily known and appreciated by those of skill inthe plastics manufacturing and welding arts, the process ofultrasonically welding two plastic parts together along an energydirector that has been formed into one of the preassembled parts allowsa bond to be formed that is tensile and resists the tendency of forcesto tear the bond apart. Specifically, the ultrasonic energy melts thepoint contact between the parts, thereby creating a seamless joint.Moreover, these types of welds can typically be strengthened by eitherincreasing the weld depth, or increasing the size of the energy directorto provide a larger weld area. Accordingly, it should be understood andappreciated herein that the precise shapes and sizes of the preassembledcomponents described herein are not essential to the present invention,particularly as a skilled artisan would understand how to maximize thesize and shapes of the components to achieve the best welded result forthe specific dispensing applicator device to be assembled.

There are, however, advantages to the embodiment of the applicator 106illustrated in FIGS. 4A, 4B, and 4C. In particular, the structure of thefirst section 114 and second section 214 is advantageous in forming asubstantially semi-circular channel 127 that encourages a therapeuticagent to be dispensed therethrough while leaving only a minimal amountof residual remaining in the channel after use. One reason for this isbecause the weld path, i.e., seamless joint 113, is disposed close tothe fluid path, i.e., channel 127. Another reason is because the channel127 has a substantially flat portion, the ribs 124, 126 can bepositioned closer to one another. As such, the channel 127 can besmaller thereby reducing the overall volume of the channel, whicheffectively reduces the amount of residual therapeutic agent remainingin the channel after dispensing the agent therethrough.

Another advantage with the illustrated embodiment of the applicator 106is the shape of the grooves 226, 228 and the ledge 224 in the secondsection 214. Each groove is substantially V-shaped and the ledge 224 issubstantially flat, as shown in FIG. 4A, such that when the first andsecond preassembled sections 114, 214 are mated and aligned togetherthere is very little, if any, flash remaining in the channel 127. Duringultrasonic welding, for example, the ultrasonic energy melts the energydirector, i.e., ledge 224, to form the joint 113 between the first andsecond sections 114, 214. In FIG. 4C, after the first section 114 andsecond section 214 are welded together, the channel 127 is formedwithout flash forming in the channel. Flash can disrupt or obstruct theflow of the therapeutic agent passing through the channel 127. Largeramounts of residual fluid can remain in the channel after thetherapeutic agent is dispensed when flash is present in the channel 127.By reducing or eliminating flash, the channel 127 maintains asubstantially semi-circular shape therethrough, which as described abovereduces the amount of residual therapeutic agent remaining in thechannel after use.

This is not, however, the case with differently shaped grooves and/orledge in the second section. In FIG. 5A, for example, a differentembodiment of a second section 514 having a top surface 517 and bottomsurface 518 is shown. In addition, a different cross-section of thesecond section 514 is illustrated in which grooves 526, 528 aretrapezoidal. The trapezoidal grooves 526, 528 are complementary to thetrapezoidal ribs 124, 126 of the first section 114 (FIG. 5B). An energydirector or ledge 524 of the second section 514 is substantially flatand therefore similar to the ledge 224 in FIG. 4A. As can be seen inFIG. 5C, after the first and second sections are welded together, thespaced ribs 124, 126 meld into grooves 526, 528 so that a seamless joint113 is formed between the two faces 117, 518, and the channel 127 isformed therebetween. Unlike the semi-circular channel 127 shown in FIG.4C, however, the mating of the trapezoidal grooves 526, 528 with thetrapezoidal ribs 126, 128 produces flash 540 which fills a portion ofthe channel 127. The flash 540 reduces the size of the channel 127 suchthat the channel 127 no longer is semi-circular. One reason flash isproduced in the channel is due to the difficulty of welding thetrapezoidal grooves 526, 528 and the trapezoidal ribs 126, 128.

In FIG. 7A, another embodiment of a second section 714 having a topsurface 717 and bottom surface 718 is shown. Moreover, the secondsection 714 includes grooves 726, 728 which are V-shaped and thereforesimilar to the grooves 226, 228 of FIG. 4A. The second section 714,however, also includes an energy director or ledge 724 that is not flat.Instead, the ledge 724 is pressed above the bottom surface 718 and has asemi-circular cross-section. The shape of the ledge 724 complementarilycorresponds with the semi-circular channel 127 of the first section 114shown in FIG. 7B. As can be seen in FIG. 7C, as the first and secondsections are welded together, the spaced ribs 124, 126 meld into grooves726, 728 so that a seamless joint 113 is formed between the two faces117, 718, and the channel is formed therebetween. The channel 127 formedbetween the first and second sections has a substantially circularcross-section, but flash 740 forms in the channel thereby inhibitingflow therethrough. Flash is produced in the channel 127 due to thedifficulty of welding the two sections together. As can be seen in FIG.7A, for example, the ledge 724 is no longer substantially flat. Inparticular, there is very little material along the ledge 724 thatcontacts the first section 114 for ultrasonically welding the twosections together. Thus, to ensure a proper bond is formed to hold thefirst and second sections together, flash fills along the edges of thechannel 127. Therefore, while it should be understood and appreciatedherein that the precise shapes and sizes of the preassembled componentsdescribed herein are not essential to the present invention, it isadvantageous for the preassembled components to comprise shapes andsizes that facilitate little to no flash.

A more detailed description of the various parts of the applicator 106will now be provided. As is particularly shown in FIGS. 6, 8, 8A and 8B,the inlet hub 110 is fluidly connected to the first section 114 by wayof a path 128 that is disposed between a pair of openings 130, 132. Asshould be understood and appreciated herein, the fluid connectionbetween the inlet hub 110 and the first section 114 defines a conduitfor receiving the therapeutic agent from the fluid delivery device 104to the groove or channel 127. More particularly, the inlet hub 110 has afirst opening 130 that is disposed at the proximal end 211 of the inlethub 110 and functions as an insertion hole for receiving the dispensingend of the fluid delivery device (such as device 104 in FIG. 1).Opposite the first opening 130 is a second opening 132, which is fluidlyconnected to the groove or channel 127 of the housing 108. As such, theinlet hub 110 is designed to functionally form an opening for the fluiddelivery device 104 so that the therapeutic agent can be easily andconveniently dispensed therefrom.

The inlet hub 110 has a pair of winged ears 111 adapted to lock to thefluid delivery device (not shown). More particularly, the fluid deliverydevice (e.g., device 104 in FIG. 1) is inserted into first opening 130and securely attached to inlet hub 110 by any fastening means known inthe art. Exemplary connection means in accordance with the presentinvention include, but are not limited to, luer lock connections. Luerlock connections are well known in the field of medicine and aretypically used for coupling a syringe or other such liquid or gas sourceto a catheter line or medical device. Moreover, as will be appreciatedand understood by those skilled within the relevant art, the luerconnectors of the present invention may be female or male in orientationand may function as luer-locking devices, luer-slip connection devicesor the like. In accordance with specific aspects of the presentinvention, the luer lock connection is achieved between the fluiddelivery device 104 and the winged ears 111 of the inlet hub 110.

As can be appreciated from the discussion above, the flow path 128undergoes a significant reduction in diameter along the direction offluid flow (i.e., from the inlet hub 110 to the distal end 112a of theoutlet 112). This is necessary to adapt the applicator for connection tolarger fluid delivery devices at the end of hub 110 on the one hand, andon the other hand to the very small channel 127 through which the fluidis moved before being dispensed from the outlet(s) 112. This reductionin diameter causes significant pressure within path 128, which in turncan cause leakage if there are any weak or vulnerable points such asweld seams along path 128. To address these structural issues, path 128is bent or shaped such that it is circuitous in nature—i.e., is not adirect route between the first and second openings 130, 132 and changesdirection one or more times. In this manner, path 128 is formed entirelywithin a single section, section 114, of the applicator, which avoidsweld seams being present for any of the structure that defines path 128.With reference to FIG. 8B, for example, the interface between the firstand second sections, i.e., joint 113 (FIG. 2), defines a plane 800 thatpasses therethrough. As shown in this illustrative embodiment, the path128 is offset from the plane 800. By locating the flow path in onesection of the applicator (as opposed to two sections defining a flowpath therebetween) and consequently eliminating all weld seams withinthe area defined by the flow path 128, the occurrence of leakage as thefluid flows between the fluid delivery device 104 and the channel 127 issubstantially reduced, if not eliminated.

The structure defining path 128 can be appreciated with reference toFIGS. 8 and 8A, wherein the conduit defined by the inlet hub 110includes a short hollow cylindrical chamber 134 that is disposed betweenthe first and second openings 130, 132 and terminates substantiallycentrally into the channel 127 at the second opening 132. Chamber 134 istypically designed such that it is dimensionally non-uniform (i.e.,varies in width and height between the first opening 130 and the secondopening 132). According to this aspect of the present invention, theinternal diameter of the chamber 134 changes to achieve the reduction indiameter and configuration needed to maintain path 128 within a singlesection 114 of the applicator. As mentioned above, the present inventorshave found that this configuration avoids leakage of the therapeuticagent as it flows between the fluid delivery device and the channel.

In certain aspects of the present invention one or more tubes or othersuch enclosed tubular structures can be internally incorporated into thestructural design of the present applicators. For instance, to avoid anyassociated leakage that may occur around the connection between thefluid delivery device and the applicator or along the joint 113 that isformed between the first and second molded sections 114, 214, one ormore chambers can be internally added into the inlet hub 110 portionand/or within the formed channel 127 of the applicator body. While suchadditional structure can be incorporated into any of the embodiments ofthe present invention without straying from the present teachings, itshould be understood and appreciated herein that such structures are notrequired. More particularly, the present inventors have found thatutilizing the bent path orientation and complementary structural designof the applicator sections makes it possible to achieve a tubelessdesign that is not only free of manifolds, but is also capable ofoperating without resultant leakage.

In certain exemplary embodiments in accordance with the presentinvention, the chamber 134 contains ridges, ledges, or other suchsimilar structures to cause a bending configuration and stepped downdiameter of the path 128. In still other aspects of the presentinvention, the path 128 is positioned below the seamless joint 113 thatis formed between the first and second sections 114, 214 and underneaththe channel 127 formed therebetween.

In accordance with certain aspects of the present invention, the secondopening 132 directs the therapeutic agent into the channel in adirection that is substantially orthogonal to the lengthwise directionof the channel 127. Such exemplary embodiment can be seen, for instance,with reference to FIGS. 8 and 8A. While the dimensions and/or geometricshape of the second opening 132 can be adjusted to fit a specific drugdelivery application, in accordance with certain aspects of the presentinvention, the opening 132 is substantially rectangular in shape.

In accordance with yet another illustrative aspect of the presentinvention, the bent path 128 comprises a substantially semi-circularportion that is connected to the conduit for receiving the therapeuticagent from the fluid delivery device 104 and the channel 127. Inaccordance with this illustrative aspect, the bent path 128 terminatesat the second opening 132, which in turn, is positioned substantiallyorthogonally relative to the substantially semi-circular portion of thebent path 128.

Once the therapeutic agent completely travels and circumnavigates thechannel 127 and reaches the distal end 112a of the one or more outlets112, it is now ready to be dispensed onto the surface or coat of theanimal. As explained above, to spread the formulation evenly over alarge surface area of the animal, the outlet 112 must be able topenetrate the animal's fur and thereby reach the animal's skin. Toaccomplish this, the outlet 112 may include one or more prongs 129 forassisting with the dispensing of the therapeutic agent onto the surfaceof the animal. In accordance with certain exemplary embodiments, theprongs 129 comprise spaced feet or tines that are configured topenetrate the fur of the animal 102 so that the applicator 106 cansubstantially reach or touch the surface of the animal's body during thedispensing of the therapeutic agent. This penetration allows a moreefficient topical and transdermal release of the agent. In addition,those of skill in the drug delivery and fluid dispensing arts willunderstand and appreciate that the addition of prongs or other suchstructural projections from the outlet 112 will discourage capillaryaction or attraction (i.e., will stop the therapeutic agent from movingupwardly along the outside of the outlet) from happening during thedispensing action. The minimization and/or elimination of such capillaryaction effects are particularly beneficial when dealing with therapeuticagents that can be considered harmful and/or dangerous.

While various illustrative embodiments incorporating the principles ofthe present teachings have been disclosed hereinabove, the presentteachings are not limited to the disclosed embodiments. Instead, thisapplication is intended to cover any variations, uses, or adaptations ofthe present teachings and use its general principles. Further, thisapplication is intended to cover such departures from the presentdisclosure as come within known or customary practice in the art towhich these teachings pertain and which fall within the limits of theappended claims.

1. An applicator for dispensing a therapeutic agent to an animal,comprising: a housing including first and second sections coupledtogether, the first and second sections defining a channel therebetweenthat includes at least one outlet; a hub integral with the first sectionand extending therefrom, the hub defining a conduit; and a bent pathconnecting the conduit to the channel; wherein the conduit, the bentpath and the channel are fluidly connected.
 2. The applicator of claim1, wherein the bent path is disposed within the first section andterminates into an opening fluidly connected to the channel.
 3. Theapplicator of claim 2, wherein the channel comprises two legsoriginating at the opening and extending in substantially oppositedirections therefrom.
 4. The applicator of claim 3, wherein the at leastone outlet comprises a pair of outlets, each leg terminating in one ofsaid outlets.
 5. The applicator of claim 2, wherein the opening directsfluid in a direction substantially orthogonal to the lengthwisedirection of the channel.
 6. The applicator of claim 1, wherein thechannel comprises a substantially semi-circular shape.
 7. The applicatorof claim 1, further comprising a connector for attachment to a fluiddelivery device.
 8. The applicator of claim 7, wherein the connector isa luer lock connector.
 9. The applicator of claim 1, further comprisingat least one prong located proximate the at least one outlet.
 10. Theapplicator of claim 9, wherein the at least one prong comprises a pairof spaced tines.
 11. The applicator of claim 9, wherein the at least oneprong comprises a pair of spaced feet.
 12. The applicator of claim 1,wherein the bent path comprises at least one turn.
 13. The applicator ofclaim 12, wherein the bent path comprises a substantially semi-circularportion connected to the conduit.
 14. The applicator of claim 13,wherein the bent path terminates in an opening fluidly connected to thechannel, the opening being positioned substantially orthogonallyrelative to the substantially semi-circular portion.
 15. The applicatorof claim 14, wherein the opening is substantially rectangular.
 16. Theapplicator of claim 1, wherein the bent path is seamless.
 17. Theapplicator of claim 1, wherein the interface between the first andsecond sections defines a plane.
 18. The applicator of claim 17, whereinthe bent path is disposed above or below the plane.
 19. The applicatorof claim 17, wherein the bent path is offset from the plane.
 20. Theapplicator of claim 17, wherein a portion of the bent path issubstantially parallel with the plane.
 21. The applicator of claim 17,wherein a portion of the bent path is substantially orthogonal to theplane.
 22. The applicator of claim 17, wherein the hub projects abovethe plane.
 23. A method of manufacturing an applicator for transdermallydispensing a therapeutic agent to an animal, comprising: providing afirst housing section including a hub portion attachable to a syringeand a pair of spaced ribs with a groove formed therebetween, the hubportion further defining a conduit; providing a second housing sectionincluding a ledge, the ledge being formed by a pair of spaced grooves;mating the pair of spaced ribs with the pair of spaced grooves to form achannel for dispensing the therapeutic agent, the channel being fluidlyconnected to the conduit by way of a bent path; and coupling the firsthousing section to the second housing section to form an applicatorbody, the applicator body defining at least one outlet for dispensingthe therapeutic agent.
 24. The method of claim 23, wherein coupling thefirst housing section to the second housing section comprisesultrasonically welding the first and second housing sections together.25. The method of claim 23, wherein the bent path is disposed in thefirst housing section and terminates in an opening fluidly connected tothe channel.
 26. The method of claim 25, wherein the bent path comprisesat least one turn.
 27. The method of claim 26, wherein the bent pathcomprises a substantially semi-circular portion connected to theconduit.
 28. The method of claim 27, wherein the opening is positionedsubstantially orthogonally relative to the substantially semi-circularportion.
 29. The method of claim 28, wherein the opening issubstantially rectangular.
 30. The method of claim 28, wherein thesubstantially semi-circular portion is smaller than the conduit and theopening is smaller than the substantially semi-circular portion.
 31. Themethod of claim 23, wherein the hub projects above a plane defined bythe first housing section.
 32. The method of claim 23, wherein the pairof spaced grooves are V-shaped.
 33. The method of claim 23, wherein thepair of spaced ribs are trapezoidal-shaped.
 34. The method of claim 23,forming a seam between the first and second housing sections.
 35. Themethod of claim 34, wherein the bent path is seamless.
 36. A method fordispensing a therapeutic agent from an applicator of the type having ahousing including first and second sections coupled together to form achannel and a hub extending from the housing that is attachable to asyringe, the method comprising: attaching the hub to a syringecontaining a therapeutic agent; placing an outlet of the applicator onor near the animal; causing the therapeutic agent to be released fromthe syringe into the applicator; passing the therapeutic agent throughthe hub, through a bent path and then into the channel; and dispensingthe therapeutic agent through the outlet onto the animal.
 37. The methodof claim 36, further comprising maintaining the therapeutic agent in onesection of the housing until it passes into the channel.
 38. The methodof claim 36, wherein the placement step comprises placing at least oneprong located proximate the at least one outlet on or near the animal.39. The method of claim 38, further comprising minimizing back pressureas the at least one prong engages the animal during administration ofthe therapeutic agent.
 40. The method of claim 36, wherein passing thetherapeutic agent through the bent path comprises causing thetherapeutic agent to change direction at least once as it is beingdispensed.
 41. The method of claim 36, wherein the dispensing stepcomprises emptying substantially all of the therapeutic agent from theapplicator.
 42. An applicator for dispensing a therapeutic agent to ananimal, comprising: a housing including a first and second sectionscoupled together, the interface between the first and second sectionsdefining a plane; a channel defined between the first and secondsections and including at least one outlet; a hub integral with thefirst section and extending therefrom, the hub defining a conduit; and apath connecting the conduit to the channel, wherein the conduit, path,and channel are fluidly connected; wherein, the path is offset from theplane.
 43. The applicator of claim 42, wherein the path is bent.
 44. Theapplicator of claim 42, wherein the path changes directions byapproximately 90°.
 45. The applicator of claim 42, wherein the path isseamless.
 46. The applicator of claim 42, wherein the path is disposedabove or below the plane.
 47. The applicator of claim 42, wherein aportion of the path is substantially parallel with the plane.
 48. Theapplicator of claim 42, wherein a portion of the path is substantiallyorthogonal to the plane.
 49. The applicator of claim 42, wherein thepath is offset from the plane.
 50. The applicator of claim 42, whereinthe channel has a substantially semi-circular cross-section.
 51. Theapplicator of claim 42, wherein a portion of the channel is defined bythe interface.
 52. The applicator of claim 42, wherein the channelcomprises a substantially flat cross-sectional portion and asubstantially semi-circular cross-sectional portion, the substantiallyflat cross-sectional portion defined by the interface and thesubstantially semi-circular cross-sectional portion defined by thesecond section.
 53. The applicator of claim 42, wherein the path isdefined in the first section.
 54. An applicator for dispensing atherapeutic agent to an animal, comprising: a housing including firstand second sections coupled together, the interface between the firstand second sections defining a seam; a channel defined between the firstand second sections and including at least one outlet; a hub integralwith the first section and extending therefrom, the hub defining aconduit; and a seamless path connecting the conduit to the channel. 55.The applicator of claim 54, wherein the path is offset from the seam.56. The applicator of claim 54, wherein the path is disposed above orbelow the seam.
 57. The applicator of claim 54, wherein the path isbent.
 58. The applicator of claim 54, wherein the path changesdirections by approximately 90°.
 59. The applicator of claim 54, whereinthe seam substantially defines a plane.
 60. The applicator of claim 59,wherein the path is offset from the plane.
 61. The applicator of claim59, wherein a portion of the path is substantially parallel to theplane.
 62. The applicator of claim 59, wherein a portion of the path issubstantially orthogonal to the plane.
 63. The applicator of claim 54,wherein a portion of the path is substantially parallel with the seam.64. The applicator of claim 54, wherein the channel comprises asubstantially flat portion that is coextensive with the seam and asubstantially semi-circular portion defined by the second section. 65.The applicator of claim 54, wherein the channel has a substantiallysemi-circular cross-section.
 66. The applicator of claim 54, wherein thepath is defined in the first section.
 67. The applicator of claim 54,further comprising a seamless conduit.
 68. An applicator for dispensinga therapeutic agent to an animal, comprising: a housing including firstand second sections coupled together, the first and second sectionsdefining a channel therebetween that includes at least one outlet; a hubintegral with the first section and extending therefrom, the hubdefining a conduit; and a path connecting the conduit to the channel;wherein, the channel has a substantially semi-circular cross-section.69. The applicator of claim 68, wherein the path is bent.
 70. Theapplicator of claim 68, wherein the path is seamless.
 71. The applicatorof claim 68, wherein the interface between the first and second sectionsdefines a plane.
 72. The applicator of claim 71, wherein the path isoffset from the plane.
 73. The applicator of claim 71, wherein the pathis disposed above or below the plane.
 74. The applicator of claim 71,wherein a portion of the path is substantially parallel with the plane.75. The applicator of claim 71, wherein a portion of the path issubstantially orthogonal to the plane.
 76. The applicator of claim 71,wherein the interface defines a seam.
 77. The applicator of claim 68,wherein the path is disposed in the first section.
 78. The applicator ofclaim 68, wherein the conduit, path, and channel are fluidly connected.